Light fixture



Jan. 11, 1966 .1. ANKROM ETAL LIGHT FIXTURE Filed June 26, 1963 ....5 NOM Y NMR E WNW M NA. .m SH EP MMM MR m Z,

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/wWlT United States Patent O 3,229,085 LIGHT FIXTURE `lames L. Ankrom, Whitehall, and Ralph C. Turner,

Columbus, Ohio, assignors to North .American Aviation,

Inc.

Filed June 26, 1963, Ser. No. 290,770 2 Claims. (Cl. 24U- 47) This invention relates''to a light fixture and particularly concerns a light fixture and lamp construction which has found application in providing improved illumination when installed in a high-temperature environment. The term high-temperature environment, as used in this application, means an environment at a temperature which is substantially greater than the recommended environmental temperature for operation of the included lamp.

An important object of our invention is to provide a light fixture construction which effectively utilizes a heatresistant incandescent lamp of the quartz tube and tungsten filament type to illuminate portions of a surrounding high-temperature environment.

Another object of this invention is to provide a light fixture construction having a vheat-resistant incandescent lamp of the quartz tube and tungsten filament type with means for improving the lamp intensity of illumination when the fixture is installed and operated in a high-temperature environment.

A still further object of this invention is to provide a light fixture construction having a heat-resistant incandescent lamp of the quartz tube and tungsten filament type with means for improving the operating lifetime and reliability of the lamp when the fixture is installed and operated in a high-temperature environment.

Other objects and advantages of this invention will become apparent during a consideration of the description and drawings.

In the drawings:

FIG. 1 is a sectional View of a preferred embodiment of the light fixture construction of our invention;

FIG. 2 is a sectional view taken at line 2-2 of FIG. l;

FIG. 3 is a sectional view taken at line 3-3 of FIG. 1; and

FIG. 4 is a sectional view taken at line 4-4 of FIG. 1.

A preferred embodiment of the light fixture construction of our invention is referenced generally as in FIG. 1 and includes a support tube 11 which has a mounting flange 12 secured thereto by a threaded connection or the like. Support tube 11 is normally mounted on a test chamber wall and operating services to and from the included heat-resistant lamp are conducted through its hollow interior. The light fixture construction 10 illustrated in FIG. 1 has been installed in interior regions of hightemperature test chambers to provide high-intensity illumination for purposes such as precision mechanical manipulation for measurement of objects undergoing test and for purposes such as observing, televising, or photographically recording such objects during testing operations. Test chambers of this nature are commonly used in connection with simulating space conditions in the temperature range of 100 F. to 1000 F. and at pressures equivalent to those in the range from atmospheric to altitudes corresponding to 120,000 feet.

Light fixture 10 also includes envelope 13 for separating other components of the fixture from test environment. In the preferred embodiment, envelope 13 takes the form of a clear, heat-resistant glass reaction flask such as is commonly used in chemical laboratories. Envelope 13 is separated from mounting flange 12 by gasket 14 and from its clamping ring 16 by the gasket designated 15. Such gaskets are preferably fabricated of asbestos laminated with stainless steel foil or like temperature-resistant materials. Ring 16 is resiliently coupled to mounting 3,229,085 Patented `Ian. 1l, 1966 ICC flange 12 through lche illustrated spring 17 and boltwasher-nut 18 combinations. 'The gaskets .and clamping ring function primarily to keep the medium within the fixture from leaking into vthe surrounding high-temperature (and perhaps low-pressure) test environment.

The light fixture 10 of this invention further includes a plenum-duct element 20 which .is mounted on base 21 and which serves to carry the fixture lamp component and its related hardware. 'The ends of duct 20 are closed. Fasteners 22 cooperate with the arcuate slots 23 and secure base 21 Vto lmounting flange 12. Use .of arcuate slots 23 permits a degree of rotational adjustment of the light xture to obtain high-level illumination in particular directions.

Light fixture 10 also includes the lamp supports 24 which are secured to `duct 20 and the nozzle stems 25 which cooperate with duct 20 at positions intermediate supports 24. A curved reflector 26 is separated from duct 20 by hollow spacers 27; it is secured in position by its cooperation with defiecto-rs 29 (see FIG. 3) and nozzle inserts 23. 'The nozzle elements 28 cooperate with nozzle stems 25 through a threaded engagement. 'Through proper sizing and contouring of the cooperating surfaces of reflector v26, spacers 27, nozzles 28, and deflectors 29, the light fixture components can be fabricated into a rigid construction. Unless stated otherwise, the heretoforedescribed light fixture components are fabricated of stainless steel alloys.

Conventional lamp receptacles 30 are secured to lamp supports 24 by fasteners 31. Electrical leads 32 and 33 are connected to a conventional source of electrical energy and cooperate with receptacles 30 through the electrical connections designated 34. Lamp 35 cooperates with lamp receptacles 30. In the preferred embodiment of our invention we utilize a heat-resistant incandescent lamp which has a quartz tube and tungsten filament construction.

In :order to obtain a high degree of illumination from lamp y35 yand in :order to improve the life and `reliability of llamp 35 during its operation in high-temperature environments, `ai-r is supplied to plenum-duct 20 by means of supply line 36 and through fitting 37 and stem 38 during opera-tion of the lamp. Such air is preferably furnished .at temperatures normally encountered exterior to the test chamber in which light fixture 10 is installed. In t-hose applications wherein comparatively llow pressures are established in the test chamber, a check valve means (not shown) may -be utilized in connection with the downstream end `of support tube 11 to minimize air leakage into the test chamber in the case of a complete lamp failure. Care must be taken that the back pressure condition in support tube 11 is not unduly high so as to restrict the flow `of air through plenum-duct 20 and the illustrated orifices of nozzles 28.

Care also must be taken in properly locating defiectors 28 -in the light fixture construction. Such elements, in combination with nozzles 28, function to reduce the operating temperatures otherwise -encountered at the terminal regions of lamp 35 that cooperate with receptacles 3l). Defiectors 29 restrict the fiow of cooling air within the light fixture so as to prevent the cooling vof surface areas of the lamp intermediate its end regions. We have observed that failure to properly rou-te cooling air significantly reduces the level of resulting illumination. Direction of airfiow to, from, and within light fixture 10 is shown by the larrows of FIG. 1.

It is to be understood that the forms of the invention herewith shown .and described are to be taken as preferred embodiments of the same, Ibut that Various changes in the pr-opoitioning, size, and detail of parts may be resorted to without departing from the spirit yof t-he invention or the scope `of the subjoined `claims.

t 3 We claim: l' 1. A light-fixture and -lampcombination for-use-in=a high-temperature environment, yand comprising:

(a) .a hollow support member, (b) .a plenum-duct means Vcarried by Aand fpr-ojected from said support member, l t (c) an elongated heat-resistant incandescent 'lamp positioned adjacent `and generally parallel to said'plenum# duct `means and having spaced-apart electrical termin-al regions, y. l' (d) nozzle means -operab-ly connected-t-osaid'plenumduct means and .arranged to dis-charge air from said 4 y.plenum-duct means in a'direction toward said lamp terminal region, (e) -deector means cooperating with sai-d lamp and restricting air discharged from said nozzle means .to init-ialdirect-contaot with only those port-ions of said lamp corresponding to said terminal regions, (f) a clear heat-resistant glass envelope'separating' said lamp and said deectors from said high-temperature environment, and I (g) conduit means for supplying pressurized air from a source exterior to sa-id ylightiixture land lamp combination to said plenum-'duct means, said deflector means and said glass envelope being arranged to direct the flow of air dischargedv yfrom said nozzle mean-s lto said hollow support member Without .signicantly cooling portions of said lamp other than sa-id lamp terminal regions.

2. A light lixture and lamp combina-tion for use in a l' Mhightemperature environment, andcomprising:

(a) duet means, U

(-b) lamp receptacle means carried by said duct means,

(c) a quartz tube .and tungsten lilament incandescent lamp positioned adjacent sa-id duct means and cooperatin g with said receptacle means,

(d) nozzle means connecting with said duct means and adapted t-o'discharge :air from said duct means in the direction of said receptacle means,

(e) deflector means separating regions Within the light xture and lamp combination which receive air from said nozzle means from regions'within said light lxture and lamp combination which surround the quartz tube portion of said incandescent lamp, and

(f) a clear heat-resistant glass envelope separating said lamp, said deilectormeans, and said receptacle means from the high-temperature environment.:

References Cited by the-Examiner UNITEDv STATES PATEITSV 1 2,295,031 V971942 Davis .g 1 24o-1114 2,449,362 9/1948' Beil et a1. Y 24o- 47 X 3,141,719 7/1964 Moore 24o-11.4 X

NORTON ANSHER, Primary Em'mn'ner.- C. R. RHODES, Assismnf'Examiner. 

2. A LIGHT FIXTURE AND LAMP COMBINATION FOR USE IN A HIGH-TEMPERATURE ENVIRONMENT, AND COMPRISING: (A) DUCT MEANS, (B) LAMP RECEPTACLE MEANS CARRIED BY SAID DUCT MEANS, (C) A QUARTZ TUBE AND TUNGSTEN FILAMENT INCANDESCENT LAMP POSITIONED ADJACENT SAID DUCT MEANS AND COOPERATING WITH SAID RECEPTACLE MEANS, (D) NOZZLE MEANS CONNECTING WITH SAID DUCT MEANS AND ADAPTED TO DISCHARGE AIR FROM SAID DUCT MEANS IN THE DIRECTION OF SAID RECEPTACLE MEANS, (E) DEFLECTOR MEANS SEPARATING REGIONS WITHIN THE LIGHT FIXTURE AND LAMP COMBINATION WHICH RECEIVE AIR FROM SAID NOZZLE MEANS FROM REGIONS WITHIN SAID LIGHT FIXTURE AND LAMP COMBINATION WHICH SURROUND THE QUARTZ TUBE PORTION OF SAID INCANDESCENT LAMP, AND (F) A CLEAR HEAT-RESISTANT GLASS ENVELOPE SEPARATING SAID LAMP, SAID DEFLECTOR MEANS, AND SAID RECEPTACLE MEANS FROM THE HIGH-TEMPERATURE ENVIRONMENT. 